text:
Why is the Priority Takeover button used?
On the sidesticks of Airbus aircraft, there is a Priority Takeover button. Wikipedia has this to say:

In typical Airbus side-stick implementations, the sticks are independent. The plane's computer either aggregates multiple inputs or a pilot can press a "priority button" to lock out inputs from the other side-stick.

On US flight 1549, the CVR transcript shows that Sully hit the Priority T/O button, after the co-pilot (Skiles) handed over control of the aircraft:

15:27:23.2 - Sully: My aircraft.
15:27:24.0 - Skiles: Your aircraft.
15:27:26.5 - FWC: Priority left.

I'm curious as to why there's a need for this button at all?
Here's a short video on YouTube, demonstrating this:

The priority button is not normally used when taking over controls from the other pilot. Even in Airbus the control hand over is done verbally. The pilot who wants the control says, 'I have controls' and the pilot who gives the control says, 'You have controls.' Or if the flying pilot wants to give the controls to the pilot monitoring, he/ she says, 'You have controls' and the pilot monitoring confirms it by saying, 'I have controls.'
As mentioned in other answers, the priority button when pressed gives side stick control to the pilot who presses it the last. If you keep holding the button and pass 40 seconds, the other side stick deactivates. It can only be activated by pressing the priority button of the other stick. The main problem with the side stick control of Airbus aircraft is not that it is mechanically not linked. The problem is how the aircraft behaves when two inputs are given at the same time. In Airbus fly by wire, the side stick inputs are algebraically added. This means, if two pilots give an opposite and an equal demand, the aircraft may not even react to the controls. Or worse, if the two pilots were to give an identical input (in the same direction) the aircraft may overreact to the controls. Below is a picture which shows this behavior. As you can see, the left pilot gives a 20% left side stick demand, while the right pilot gives a 30% left demand. The aircraft adds up the inputs and the net input becomes a 50% left roll demand.

What are the risks associated with dual inputs? The main risk is that the aircraft might behave inappropriately to what the pilots want. For example, in the flare to the landing, if two pilots put in inputs to the side stick, the aircraft may under flare (opposite inputs) and the result can be a hard landing. Or if the inputs are given in the same direction (nose up), the resulting over flare may cause a tail strike. This is where the priority button becomes extremely crucial. If you for instance see the other pilot not flaring during the landing, you say I have controls, press the priority button and do the flare yourself. This ensures the other pilot can no longer control the aircraft. This is particularly important in training flights with a new pilot who for example fails to flare at the right time. Many a times new pilots tend to be nervous (natural human behavior) and even when the instructor says he has controls (after seeing what is happening), because of nervousness the trainee can unknowingly manipulate the controls. This can develop into a very dangerous situation where neither of the pilots know who has the controls. The priority button really helps in these type of dynamic situations. To ensure that the pilots are aware that there is a dual input, if the inputs meet a certain threshold, a 'dual input' aural alert comes on.
In case of Capt. Sully, we cannot be entirely sure why he pressed the priority button after saying he has controls. It might be because they were in a dire situation (dual engine flame out) and he did not want his first officer to unknowingly add any inputs to his inputs. Usually, in normal flights as said above changing over controls do not require the use of priority button.

Can you explain why Air France Flight 447 pilots failed to understand that there was dual input situation when the first officer panicked? Do some other warnings override the warning about dual input?

@MikkoRantalainen Yeah, in the case of AFR 447, the cockpit is filled with alarms and warnings, so they probably didn't hear the dual input warning.

It's been several years since I worked at United's flight training center, but if my memory serves me, it is there in case the system is receiving input that the pilot wants to exclude. As was explained to me, an example of this would be the other pilot becoming incapacitated, with their body leaning against the sidestick. In this case, one would want to use the Priority Takeover button to eliminate the other pilot's input.
In Captain Sullenberger's case, it is likely that he wanted to ensure that First Officer Skiles wasn't providing any control inputs that would work against his control inputs.
Now, it is also my understanding that such functionality is not useful in a "hostile takeover" event, since the other pilot can also attempt a priority takeover (or use physical force, due to the close proximity of the two pilots).

The "Priority Takeover" override capability is particularly important in the Airbus control implementation because the sidesticks aren't linked: The pilots can't know if the other seat is giving a conflicting control input by feeling a force on the stick, so using the button ensures that there is no conflict: the stick with priority is the one the system is listening to.

That is correct. One of the unique aspects of Airbus flight controls is that they provide no feedback (other than self-centering).

I believe the priority takeover also gives priority over autopilot, which was most likely on already.

@JanHudec I thought the button doubled as A/P disconnect. I.e. 1 press for A/P disco, another press for Priority T/O. I could be wrong though...

@DannyBeckett: In that we would agree, yes (I don't know the exact procedure, just that it disconnects autopilot). And most likely here the reason to use it in case of US1549 was to make sure autopilot was disconnected.

@JanHudec, yes the button is used for both autopilot disconnect and priority takeover. Note that one merely has to tap the button to disconnect autopilot, but it must be held down for priority takeover. It is not possible to perform a priority takeover without disconnecting the autopilot first; there is no "control wheel steering" functionality on the Airbus.  Additionally, autotrottle is disengaged separately via the disconnect buttons located on the throttle handles themselves.

@newmanth: Well, my point is that the reason captain Sullenberger pressed it was more likely to ensure autopilot was not on than to ensure his copilot, who acknowledged handing over controls, was not providing any input.

@JanHudec, You'd have to ask Capt Sullenberger for an authoritative answer on that :P. I do know most pilots (myself included) will not use autopilot while still being vectored out of the terminal area, since it's easier to just hand fly in this phase of flight. Many airlines have procedures to verbalize configuration changes (autopilot included) so that both pilots know the current state of the aircraft. Additionally, when the A/P is disengaged, Airbuses make a loud 'CHIRP, CHIRP, CHIRP' noise to alert the crew, which did't happen in this case, since F/O Skiles was hand flying at the time.

@newmanth It can also be some thinking like "I want to be sure I have control" that trigger this reaction, whatever the situation (no thinking about if this is the autopilot or the F/O that can control the aircraft, the action to take over is the same).

I'm not sure it exactly answers your question, but there is an excellent example of why this feature ought to always be used in an emergency situation.
Air France Flight 447 was an Airbus A330, I'm not entirely certain if it had this feature (I assume so?)  Anyway, it went into a stall somewhere near cruise altitude and the co-pilot, for some unknown reason, kept pulling back on the right stick.  Eventually the plane was at a 40 degree incline and losing altitude quickly.  The pilot on the left stick noticed the the stall and tried to push the plane forward to correct, but found the controls to be unresponsive, he was apparently unaware that the right stick was pulled fully back. The plane stayed in that stall all the way until it crashed into the Atlantic Ocean.
In an emergency, it's really really important to have a single input or a "single source of truth", not matter what industry you're in (I hear it all the time in software development anyway.)  I'd argue that this is the main reason they have that override switch.

In this particular example, the PIC did recognize the situation and told the FO to stop, but it was already too late.

Eventually, yes, the PIC came in and figured out what was going on.

As far as I recall the priority button suppresses the other stick and autopilot. Since it is right under the thumb on the side-stick, that makes it quicker way to disconnect autopilot than navigating the other hand to the flight management panel.
The overall idea is that when the pilot needs to make manual input quickly they simply push that button and it will ensure that input will be obeyed, so they don't need to think what state the system was in.
Note, that the priority take-over button will disconnect autopilot immediately when pressed, but it only disables the other side-stick while held down, or permanently when held down for more than 40 seconds. The last case is primarily for situations when the other pilot is incapacitated holding their side-stick deflected or when the other side-stick fails.

A prime reason for this is the fact that the Airbus sidesticks are not connected mechanically, unlike the center control columns of other aircraft. In the event of conflicting inputs from both pilots, such a condition would not be readily apparent. With mechanically connected columns, conflicting input is not possible, without both pilots being aware that the other was trying to do something different.
As Jay Carr mentioned, this was one of the reasons that led to the AF447 crash - conflicting stick inputs, and apparently neither pilot was aware of that situation, as they would have been with mechanically connected columns. That was an avoidable accident, on several levels.
It's surprising that Airbus came up with dual disconnected sidesticks and didn't consider the possibility of conflicting inputs, certainly didn't do a very good job of alerting the pilots that such a condition existed. In retrospect, the computer should be screaming bloody murder at the pilots if it detects both sidesticks in use simultaneously - a situation that should never happen.

AF447 flight should have shouted "dual input" all the time both pilots tried to recover the plane (or actually one pilot was frozen on panic and another tried to recover the plane). Was the "STALL" warning overriding the "dual input" warning?


text:
Does the NTSB provide CVR audio recordings alongside transcripts in accident reports?
Reading the NTSB's accident report on US1549, there is a transcript of the CVR from page 149 onwards in the PDF (marked as page 130 on hardcopy).
Small clips of the ATC/crew communications exist, but I'm curious to know whether the NTSB also release the full audio recording, per the transcript provided? It's much longer than other clips I can find online.

Related: Can I get official recordings of ATC audio? (asks for FAA, not NTSB).

No. Federal law prohibits the NTSB from releasing any CVR recordings, and the NTSB notes that they are exempt from FOIA requests. The same law requires them to release a transcript, like the ones seen in accident reports, if the transcript is relevant to the accident or incident.
See 49 U.S.C. § 1114(c):

(1) The Board may not disclose publicly any part of a cockpit voice or video recorder recording or transcript of oral communications by and between flight crew members and ground stations related to an accident or incident investigated by the Board. However, the Board shall make public any part of a transcript or any written depiction of visual information the Board decides is relevant to the accident or incident—
(A) if the Board holds a public hearing on the accident or incident, at the time of the hearing; or
(B) if the Board does not hold a public hearing, at the time a majority of the other factual reports on the accident or incident are placed in the public docket.

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What items could you bring on-board to maximise your chance of survival in an emergency?
A question on Travel (Are parachutes allowed on airplanes as cabin baggage?) got me to wondering: hypothetically, what items could the "über-paranoid" passenger or pilot bring on-board to potentially save their life in an emergency?
I.e. a parachute, oxygen, a portable smoke hood?
What are the technicalities? I.e. would a parachute be of any use above a certain altitude? What about with oxygen?

I think this is tricky to answer, at least without making the question much more specific. I suspect you're asking about surviving a crash landing - or ditching? - in a large airliner, but an "emergency" could be almost anything and are you including smaller aircraft too? If you consider terrain/weather factors, possible injuries or survival in a hostile environment after landing then the question becomes impossibly broad.

@Pondlife I'm referring to all possible emergencies - what [hypothetically] could someone bring on-board? I'm particularly interested in something happening at high altitude, i.e. a mid-air collision or fire. To put it another way, presume you're in a mid-air collision and you've brought a parachute; will you live?

Thanks for the extra information, but "all possible emergencies" is too broad to answer. Yes, passengers and crew have successfully parachuted from a burning aircraft in very specific circumstances, but a mid-air involving two airliners would have been a different story. I'm not sure what answer you expect here since you're trying to cover so many possibilities and the question is basically a 'what if' one anyway.

Bringing oxygen on a plane is far more likely to cause an emergency than to help you escape one.

@Pondlife I'll do the research online and answer the question myself later tonight if nobody else has by then... I'm basically curious to know if there's a [short] exhaustive list of things that might help you live, and the technicalities behind each of them. I.e. preliminary research shows that only oxygen-dependent people can bring oxygen on-board in the USA; and a parachute would be useless at high altitudes, due to the 500mph+ winds.

You face a far greater risk from DVT than from any inflight emergency.  If you want to survive your flight, the best advice is to avoid restrictive clothing, and bring some exercise bands.

@abelenky A good point, but DVT isn't an aircraft emergency. It seems people are answering an altogether different question here...

Most likely you will also not get a chute past security.

@yankeekilo Actually, parachutes are permitted in carry-on. Click the link in the question! The TSA have a section on their website specifically allowing them, as do a number of airlines.

@DannyBeckett wow, I really never would have guessed that. Noted as my favorite factoid of the day! Even though HA(LO) gear looks quite bulky, so you´d pay extra :D

@yankeekilo That factoid is exactly why I'm interested to know if a chute would even be of any use! It seems everyone else thinks its a "ridiculous" question.

@DannyBeckett not ridiculous, but perhaps a bit broad. You get my vote for your research anyway.

@DannyBeckett I think a question which simply asks whether or not it would be "possible or practical to parachute from a commercial airliner in an emergency" would be a more constructive and answerable question - since that seems to be the question you really want answered anyway.

@BretCopeland Essentially, yes. As an aside though, in practicality, I guess a smoke hood would be more useful; and I can't imagine there'd be many more items you could bring.

Quite unbelievably, I just found a video of a mid-air collision where 10 skydivers jump out of the damaged plane to safety: http://usnews.nbcnews.com/_news/2013/11/04/21308806-exclusive-images-show-skydivers-terrifying-collision-and-chaotic-plunge

Gizmodo have just written an article about this: Why Don’t Commercial Airplanes Have Parachutes for Passengers?

Wear closed shoes, especially on take off and landing. Sit properly in the seat; it is designed for feet flat on floor, spine in the upright position. Wear seatbelt properly. Sit near a rear exit.

Obviously, a jetpack!!

This wikipedia article lists a handful of cases in addition to the famous DB Cooper incident where people have parachuted from an airliner successfully-- en.wikipedia.org/wiki/Airstair

Most of the items you can bring with you to maximize your chances of surviving an in-flight emergency are items you're not going to be allowed to bring with you.
About the only things I could recommend bringing along on a commercial flight are your cellphone and a personal locator beacon (PLB) of some kind, but frankly if your airliner goes down ATC is going to know where you were when they lost contact, (and the plane has an Emergency Locator Transmitter already).
You should also wear sensible clothing -- natural fibers like wool or cotton are the order of the day if in-flight fire is a concern. Polyester or other synthetic fabrics will melt to your skin and cause you to have a Bad Time.

More directly addressing your question though, the items that spring immediately to my mind (and why you probably won't be taking them with you) are:

A parachute (what prompted your question)
Sure, you can bring your parachute. It's kind of a useless security blanket though.
From cruise flight you'd basically be executing a high-altitude jump (let's say a HALO jump, because you want to get down as quick as you can). You would require oxygen to remain conscious longer than about 30-45 seconds (though an automatic-opening chute may save you here), as well as protective clothing to survive the low temperatures while you're free-falling.
Those concerns aside, remember that airliner cabins are pressurized and the doors are typically "plug doors" that open inward. No human is strong enough to open that door with the cabin pressurized, and if you've lost cabin pressure for some reason you're better off putting on that little drop-down oxygen mask like the nice flight attendant told you to in the safety briefing. You're not going to save yourself if you pass out from hypoxia while putting on your chute and trying to get to the door.
An oxygen mask / smoke hood can be useful in a fire.

Most airlines are not going to let you carry an oxygen cylinder onto the plane (as others pointed out in comments, oxygen and in-flight fires can cause more problems than it solves).  That holds true for pretty much any kind of compressed gas because really, how do they know what's in that tank?
A smoke hood using a filter (or a sealed rebreather hood) with no compressed air supply may make it past security, but ask yourself honestly: "Am I proficient enough to use an emergency escape smoke hood in an in-flight emergency?" -- If you can't answer "yes" you're probably putting yourself (and others) in more danger wasting time donning the hood versus just getting out of the aircraft.

A life vest (if traveling over water)
This is overkill on an airliner (though those of us that fly little planes should seriously consider flotation devices when flying over water).
Your airline seat cushion really CAN be used as a flotation device. Those big yellow slides also detach from the plane and make marvelous floats. Frankly if you need any of these items you're in a situation where having your own Mae West isn't going to really enhance your chances of survival.
A utility knife capable of cutting your seatbelt
This is incredibly useful for a bunch of reasons, not just cutting your way out of your seatbelt. In fact I keep one in my plane. Sharp and/or pointy things make airport security nervous though - if you try to take such an item on an airline flight it will likely be taken away from you before you get anywhere near the plane.
Food and Water
Useful if you have to make an emergency landing in a remote area, but frankly airliners already have beverages (some may even still have food).
If you're carrying a light snack you're as set as you're going to be in this department.
Emergency Blankets
Nice to have, but most commercial aircraft already have shock blankets on board (and much like food/water, this is really only useful if you have an otherwise uneventful landing in a remote area).
If it makes you feel better to have your own blanket you can get pre-packed ones that can fit in basically any carry-on for about $5-10.
Signal flares
Again, mainly useful if you have an emergency landing in a remote area (and your PLB and the plane's ELT don't work for some reason). Flares are good both for signaling rescuers and for starting fires to keep warm.
I don't know if rescue flares are still routinely carried on commercial airliners, but I can say with reasonable certainty that you will not be allowed to carry on your own. They don't let you smoke on most airlines these days - they're certainly not going to let you carry on a self-igniting flare!

Note that oxygen is also provided by the airline ("if the overhead masks should deploy....").  Since smoke fumes and fire kill the most people, I would vote for the smoke hood and a nomex fire suit.  :-)

@lnafziger This is true (and in fact as others have pointed out oxygen-dependent patients may be allowed to fly with an oxygen bottle as long as the oxygen supply is not deemed to be a hazard). The on-board oxygen masks are a special case though - they're usually connected to either a central oxygen tank or to chemical oxygen generators, both which are not without their own hazards in the event of an in-flight fire (chemical oxygen generators feature prominently in at least one NTSB report), but the risks are known & designed for.

Sure, I was just saying that there isn't much need to bring your own since if there is a need for oxygen (depressurization) then they already have it there for you.

Yup; when my plane crashes in a swamp and I'm knee deep in kerosene with 80 other desperate survivors, remind me to run like hell before that one guy gets excited and fires his signal flare.

"but frankly if your airliner goes down ATC is going to know where you were when they lost contact"
One certainly would have thought so, but recent events suggest that this is not as dependable as one would have assumed in certain parts of the world.

A life vest will be already on board on any flight over significant body of water and many other flights (in Europe it usually is there even if you don't fly anywhere near any water, because they just have standard equipment in their fleet, but I believe regional airlines that never fly across water may not have them).

A utility knife capable of cutting your seatbelt: Note that you can bring obsidian stones with you. They are just as sharp as knives for the first few cuts, and are not detected by a metal detector, x-ray, or other means.

The two most important things you can bring on board that are likely to save your life in an emergency are a physically fit body and a ticket to a seat in an exit row.

Paying attention to that safety briefing is also a good way to maximize your chances of survival. If your don't know where the nearest exits are you'll have a tough time getting to them in an emergency.

Add common sense & a tendency not to panic in high-stress situations.

Although this technically answers the question, it isn't quite what I'm looking for. I'm wondering what outside items you could bring on-board to maximise your chance of survival.

@DannyBeckett - If there was some item that could measurably increase occupant safety, don't you think it would already be required equipment?

I would like to add a thunderer whistle to the list.

A thunderer whistle is an essential survival tool not only after a plane crash. It enables you to be heard miles away when rescue teams are looking for you. It helps them find you quicker, and if you're capable to, you can also morse. Finally, a thunderer whistle is small and light. I have one in my flight bag.

I've seen it suggested many times that those seated near the rear of aircraft seem to have higher survival rates in crashes than those seated near the front.

Survival rates for various parts of the passenger cabin, based on an analysis of all commercial jet crashes in the United States since 1971 where detailed seating charts were available. (Illustration by Gil Ahn. Diagram Courtesy of seatguru.com.)

Source: Safest Seat on a Plane: PM Investigates How to Survive a Crash on  Popular Mechanics

Thanks for your answer, but it isn't quite what I'm looking for. Essentially, I'm wondering how you might be able to survive a high altitude emergency, i.e. by jumping out of the plane.

Notice that the worst seat in the house is in the cockpit....

...followed by first class.

I am aware about the railway disaster where a passenger train hit a fuel cistern (1975, Žąsliai, Lithuania).
In this disaster, it was the synthetic clothing that burned and melted easily that significantly reduced chances of successfully escaping from the burning coaches.
This experience probably is applicable for some aircraft disasters as well.

I read once a book about survival which I can't find now. Basically it was an investigation from a journalist about how different people dealt with situations where their life was at stake.
One of the situations was obviously a plane crash. The one thing that I took from that book is that in the case of an emergency, you simply act by reflexes; you don't have time to think. Therefore it is very important that you memorize the safety instructions at the beginning of the flight.
Yes, those silly instructions that you ignore while checking Facebook can save your life. So know where your nearest exit is, how to use the oxygen mask and where the life vest is.

The vast majority of airline accidents are survivable.  Obviously then, the vast majority of airline accidents end with a stationary aircraft on the ground.  It may be bent or broken or on fire, but it's on the ground and it's not moving.
Some things about flying as a passenger are within your control and many are not.  Putting aside any factors of age, fitness, gender, or where exactly you are sitting, there are a couple of things that you can do to maximize your odds of getting out alive.

Pay attention to where you are sitting relative to the exits.  Count the number of rows between you and the nearest exit, and the nearest exit in the opposite direction.  Say these numbers to yourself in your head.
Fasten your seat belt as tight as you can low down across your hips/upper thighs.  You can loosen it up later after you're airborne or clear of the runway, but for the actual takeoff roll and landing rollout, be willing to be slightly uncomfortable because of how tight your seat belt is.
Pay attention.  During the takeoff roll and landing, don't have your head down looking at anything.  Look up and pay attention to the sounds of the aircraft and the movements.  If something goes wrong, you'll be much better prepared to take quick action if you need to if you're paying attention.
If the landing or takeoff end badly and you know it, take action as soon as the aircraft stops moving.  There's a strong tendency for people to wait for directions after an accident, so be the one who gives them.  It doesn't matter particularly what you say as long as it's along the lines of "get up, hurry, move, go that way!"
Wear shoes.  At least for takeoff and landing, wear actual shoes that cover your feet and can't come off easily.  When I was a flight attendant, we were told unofficially that wearing shoes was a huge predictor of who got off a wrecked, burning aircraft alive.  If you do all of the 4 previous things right and are barefoot, your odds go down dramatically. And it's amazing how violent a crash can be to the point that flip flops and loafers are often missing from victim's feet.

As far as the OP, goes, I guess the answer is 1. your head full of correct thinking and 2.  shoes.

Get a smoke hood...Its an extreme No Brainer: read on.
In a special program Sixty Minutes I believe,  it was explained that most fatalities occur on the ground...Fires, smoke, and were survivable. that is  if you could see, breathe, and your hair was not on fire. You can always use the smoke hood in your hotel as well.  There are a few approved "passive" types that cover your head completely, seal at the neck, and have filtration to give you a couple of minutes to evacuate. The hood portion is Kapton fire retardant material so the dripping flaming plastic from the ceiling will be less likely to set your hair on fire. The acidic fumes will not get to your eyes so you will be better equipped to find the door in the dense smoke.  better to have and not need than to need and not have.
From Canada's TSB Aviation Safety Study SA9501:

2.3 The Cabin Environment
The presence of fire, smoke, or toxic fumes created evacuation difficulties in 11 of the evacuations reviewed. (This issue is discussed further in Section 3.)
In 3 of these 11 evacuations, there were 89 deaths and 25 serious injuries.
Visibility was severely restricted or totally obscured in four evacuations where a cabin fire existed.
The combination of fire, smoke, and/or toxic fumes was lethal in three of four occurrences where fatalities were incurred.
3.0 FIRE, SMOKE, AND TOXIC FUMES
Fire, smoke, and/or toxic fumes were present in three of four fatal
accidents examined in this study and caused serious injuries to many
of the survivors.
The following excerpts from the report of the occurrence at Calgary
help to illustrate the severe conditions that can exist during an
evacuation when fire, smoke, and/or toxic fumes are present.
Shortly after the evacuation commenced, fire melted windows along the
left side of the aircraft. When the windows melted through, heat and
smoke entered the aircraft, and the cabin environment quickly
deteriorated. Substantial quantities of smoke also entered through the
right over-wing exit and right rear service door.
Those passengers who had been seated beside the windows nearest the
fire experienced some singeing of hair and clothing. Smoke obscured
visibility almost totally during the latter stages of the evacuation.
Smoke conditions were worse in the aft section of the cabin.
Passengers who exited via the rear exit reported that they were unable
to see the exit and were required to follow the person ahead to locate
it. By the time most had reached this exit, the smoke had lowered to
about knee height. The bottom portion of the door and the slide were
all that was visible. The passenger who was the last one to exit via
the over-wing exit reported he had to drop to his knees to breathe
fresh air before he was able to reach the exit. Only when he neared
the exit, did it become visible through the smoke. (A84H0003)
The presence of fire, smoke, and/or toxic fumes presented the greatest
risk to a successful evacuation by restricting visibility, limiting
communications, reducing the number of available exits, affecting
passenger behaviour, and decreasing occupants' mental and physical
capacities. Fire, smoke, and/or toxic fumes were identified as hazards
in 11 evacuations and were present in three of four fatal occurrences.
Thick black smoke severely restricted or totally obscured visibility
in four occurrences where a cabin fire existed. As a result,
passengers were unable to see the exits. In Cincinnati, the location
of two passengers' bodies indicated that, in their attempt to get out
of the aircraft, they had unknowingly passed an available exit.5
In the same occurrence, cabin attendants who were exposed to smoke and
toxic fumes experienced great difficulty communicating orally. As a
result, some passengers were unable to hear the emergency briefing.
A reduction in the number of available exits was recorded in nine
occurrences. Fire and smoke also blocked egress in those occurrences
where breaks in the fuselage were avenues of escape.
In three occurrences, it was found that burns and inhalation of smoke
and toxic fumes limited passengers' mental and physical abilities,
thereby obstructing or prohibiting their attempts to reach, operate,
and negotiate emergency exits or egress through breaks in the
fuselage.
Existing Risk Mitigation
There are several regulatory provisions which are designed to protect
aircraft occupants from the risks associated with the presence of
fire, smoke, and toxic fumes and thus increase the chances for a
successful evacuation. As well, the industry has developed operating
procedures to reduce or eliminate the effects of these hazards to crew
and passengers. In the light of the high risks associated with the
presence of fire and smoke as evidenced by the Canadian experience,
the Board examined two areas of risk mitigation related to fire,
smoke, and toxic fumes, namely protective breathing equipment for both
crew members and passengers, and fire hardening of aircraft interiors.
These areas were examined in the context of their potential to limit
the risks encountered during the evacuation process.
3.1 Protective Breathing Equipment
She [the flight attendant] saw light grey smoke had filled the
lavatory from the floor to the ceiling, but she saw no flames. The
flight attendant closed the door but not before she had become dizzy
from inhaling the smoke. (A83F0006)
Twenty-three passengers died from smoke and toxic fume inhalation as a
result of an in-flight fire in the rear lavatory of a DC-9. (A83F0006)
The lavatory was completely filled with smoke that severely restricted
visibility and impaired breathing. As a result, the cabin attendant
in-charge was unable to locate the source and exact nature of the fire
or to fight it effectively. In the investigation report of this
occurrence, the National Transportation Safety Board (NTSB) stated;
"... had an oxygen bottle with a full-face smoke mask been available
and used, it might have encouraged and enabled him to take immediate
and aggressive actions to fight the fire, as set forth in the company
manual."6
Canadian Industry Practice
In addition to the protective breathing equipment (PBE) provided for
the flight crew, some air carriers provide at least one portable PBE
unit for crew members who may be required to fight cabin fires on
non-combi aircraft. Such units are normally located on the flight
deck. Portable PBE is carried either to fulfil operating requirements,
as specified in the type certification of some aircraft, or as a
result of a particular carrier's desire to enhance cabin attendants'
capabilities to fight fires. The TSB has been advised that some air
carriers do carry PBE units in the cabin.
Regulations in the United States and United Kingdom
PBE for flight crews has been a mandatory requirement in the United
States for over 45 years. In 1987, partly as a result of the DC-9
occurrence at Cincinnati, the FAA amended Federal Aviation Regulation
(FAR) 121-337, Protective Breathing Equipment, such that air carriers
operating transport category aircraft must provide PBE, not only to
flight crew, but also to other crew members who are responsible for
fighting fires on board the aircraft. One portable PBE unit is
required at each hand-held extinguisher station. There is no
requirement to provide passengers with any form of PBE; indeed, there
are regulations which specifically prohibit passengers from bringing
PBE which contains compressed oxygen on board air transport aircraft.
In the United Kingdom, PBE is mandatory for both flight and cabin
crew. Such equipment must be provided for each cabin attendant
required to be carried under safety regulations and must be readily
accessible to them at their assigned stations. Supernumerary cabin
attendants would not figure in the number of PBE units required. PBE
is not required for passengers.
Transport Canada Regulations
ANO Series II, No. 9, the Oxygen Equipment Order, stipulates PBE
requirements for operation of large commercial aircraft. PBE is
defined in the Order as "... equipment to cover the eyes, nose and
mouth, or the nose and mouth if accessory equipment is provided to
protect the eyes, that will protect the wearer from the effects of
smoke, carbon dioxide or other harmful gases." In accordance with the
Order, air carriers operating pressurized aircraft in a commercial air
service must provide "each flight crew member on duty at his station
protective breathing equipment." There is no regulatory requirement to
provide cabin attendants, other than those working on combi aircraft,
with PBE.7 Nevertheless, ANO Series VII No. 2, Section 45, "Emergency
Procedures Training" clearly implies that all cabin attendants are
expected to fight cabin fire.
Similarly, there is no regulatory requirement to provide passengers
with PBE. Several years ago, Transport Canada participated in an
international feasibility study addressing the safety benefit of
providing "smoke hoods"8 for passengers. The results of the study were
published by the CAA in 1987.9 It was concluded that the number of
lives saved by smoke hoods each year would be "modest" (179 lives over
20 years, or approximately 9 lives per year world-wide) and that the
time required to don the apparatus might increase the time required to
evacuate an aircraft, thereby causing a greater loss of life.
Mandatory carriage of smoke hoods as passenger safety equipment was
not recommended. Neither Transport Canada nor any of the other
countries who participated in the study (United Kingdom, United States
and France) have subsequently proposed any regulatory amendments to
require PBE for passengers.10
There remains the question of voluntary carriage of passenger PBE, by
carriers
or by individuals. In accordance with The Transportation of Dangerous
Goods Act, passengers travelling on Canadian commercial air carriers
are prohibited from bringing on board passenger transport aircraft
those smoke hoods which provide oxygen from a cylinder of compressed
gas. Introduction of oxygen into the cabin environment, other than the
oxygen found in the emergency overhead oxygen-mask system, which is
designed for passenger use during an in-flight depressurization, is
currently viewed as a hazard in the event of an in-flight fire.
However, small, gaseous oxygen or air cylinders required by passengers
for medical use are accepted as carry-on baggage or, with the
operator's approval, as checked baggage. Canada has recently asked
ICAO to examine, from a dangerous goods perspective, the issue of
smoke hoods containing a cylinder of compressed gas.
Passengers are permitted to carry filtration-type smoke hoods on board
Canadian aircraft but current filtration-type smoke hoods would not be
as effective as smoke hoods which have a self-contained source of
breathable oxygen.
Recommendations
In the context of the actual evacuation process, there is no direct
evidence that a lack of PBE for cabin crew resulted in fatalities or
injuries during evacuations. Yet, there is a paradox in that cabin
attendants are expected to fight cabin fires, but, in many cases, they
are not provided with PBE in the aircraft cabin. Ready access to
portable PBE could improve their ability to fight fires and have the
effect of reducing the risks faced by occupants during an evacuation.
Therefore, the Board recommends that:
The Department of Transport require that sufficient portable
protective breathing equipment units with full-face masks be carried
in the passenger cabins of transport aircraft for cabin crew. A95-01
In the light of the number of fatalities that occur when fire, smoke,
and/or toxic fumes are present, the Board believes that further
research is required to determine whether passengers should be given
the opportunity to carry appropriate protective breathing equipment.
Accordingly, the Board recommends that:
The Department of Transport re-evaluate research regarding protective
breathing equipment (PBE) for passengers with a view to determining
the feasibility of the carriage of appropriate protective breathing
equipment, on a voluntary basis. A95-02

You should summarize your source rather than just pasting it all verbatim into your answer.

authors: ʇolɐǝz ǝɥʇ qoq

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text:
Which aircraft feature stock exterior cameras?
Watching a video on YouTube of an A340-600 takeoff, I noticed that it has at least two exterior cameras — one for lining up the nosewheel, and the other on the tailfin:

After the NTSB recommended the use of exterior cameras in 2012, I'm wondering how widespread these are? Which models of Airbus aircraft have them? Do any Boeings?
Do these record or are they realtime-only?

Apparently, it is catching on.
Boeing mentions it is unique to 777, probably the first one to have cameras.

A feature unique to the 777-300ER and 777-300 flight deck is the
  Ground Maneuver Camera System (GMCS), designed to assist the pilot in
  ground maneuvering of the 777-300 with camera views of the nose gear
  and main gear areas. The cameras are on the leading edge of the left
  and right horizontal stabilizers and the underside of the fuselage and
  are used during ground maneuvering. The images are displayed at the
  Multi-Functional Display positions in the flight deck in a three-way
  split format.

Boeing also has patents for this: here and here.
I am not sure if these patents prevents others to have them, because many business jets already had cameras on, and this trend is catching on even for passengers on commercials plans.
Airbus mentions this too for A340:

The A340-500 and −600 has taxi cameras to help the pilots during
  ground maneuvers.

I guess it has several different names, probably because of pending patents etc.

As far as the recording goes, I could not find any information.

The A380 has external cameras as well.

@fooot I agree. I am sure 787 has them too. Probably all new planes have them.

Does the 787 have them? I can't find any mention.

@fooot I cannot find that either. It doesn't look like Ground Maneuver Camera System (GMCS) was only developed for 777.

For what it's worth, at least on Cathay Pacific, you could watch the camera mounted underneath the fuselage on the passenger IFE system on their 777-300ERs. I didn't see a way to select the other cameras, though. Still, it was a nice feature.

I fly the A320 and 321 which, at our company, had been equipped with nose cameras. The pictures, though, where just used for passenger entertainment during takeoff and landing and keep being disconnected by maintenance when failed due to high spare parts costs.


text:
Will the new USAF trainer Boeing–Saab T-7 Red Hawk have weapons?
Will the new USAF jet trainer, the Boeing–Saab T-7 Red Hawk, have weapons?
I see the mention of the possibility of hardpoints e.g. here:
https://www.thedrive.com/the-war-zone/42760/air-force-wants-hundreds-more-jet-trainers-despite-already-buying-t-7-red-hawks
And this one:
https://www.thedrive.com/the-war-zone/35224/australia-serbia-emerge-as-first-potential-t-7a-red-hawk-jet-trainer-export-customers
Mentions that it might replace the J-22 for the Serbian air force. However, to replace that, it seems implied that the T-7 will be able to carry out the combat role of the J-22.
Whereas other sources, don't mention it at all.
In any case, it is still unclear to me.
Is there a more recent and more serious source that is definitive in this matter? It seems to me like this would be a very big deal -- will the aircraft have all the plumbing, wiring, fire control radar, etc. that is needed to basically be, a light attack aircraft? Or not?

Small point, you don't need a fire control radar for the ground attack mission - the A-10 seems to do okay without one. That aside, interesting question!

Maybe this article is helpful

Flying a modern fighter is easily as much about managing all the systems as it is airmanship.  You need to be able to interact with a smart weapon in a training scenario.  Rather than make the aircraft simulate the weapon's sensors and systems (for many weapons), it seems very reasonable to design a trainer to carry the weapons you want to use in real combat.
The T-7 is designed for export and it seems very likely that it will both be sold as a trainer -- and armed and sold as an attack or fighter-attack aircraft.
Boeing will not want to undermine F-15 and F-18 sales -- and Saab will not want to undermine the Gripen.  However, when the situation is right, they will look to sell an armed variant.

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text:
Is making faster military fighters even practical?
I was curious after reading a book on Cold War plane development about the Soviet ideology of making increasingly powerful jets that could break Mach 3 and so on. With the advent of BVRAAM's such as the Meteor and lasers that are already being scaled down, what are the advantages to increasing the top speed or cruise speed of a fighter jet?

Related, maybe a dupe?

No I already know how the practical speed barrier prohibits some advances, but I was curious as to if increasing speed significantly was possible, would it strategically/tactically be advisable?

Related to "why are there no Mach 4 fighters": https://aviation.stackexchange.com/questions/44530/why-are-there-no-mach-4-fighter-planes/44595#44595

Fast interceptors is still useful if the defense side has a large attack surface and not a lot of alarm time, .e.g. when the interceptor arrives the attacker might have already dropped the payload. But after the cold war the only place that still suffer this kind of threat is probably Japan and east Europe which seem to have chosen not to envelop a effective high speed interceptor.

In the 1960, faster fighters were seen as desirable as they could outrun 1960s technology missiles to an extent (see the reports of SR-71s being fired on but never hit by SAMs). Of course, missile manufacturers saw this and developed faster missiles and longer-range radars to negate this advantage. And as it is much easier to make a missile faster than it is to make a large aircraft faster, that's an arms race the airplane manufacturers always lose.
While high speed allows you to outrun missiles, it also reduces maneuverability: at Mach 3, a constant-G turn will be much larger than turning at the same G level at Mach 1.

what are the advantages to increasing the top speed or cruise speed of
  a fighter jet?

It's often thought that speed is used to avoid attack, but that is rarely successful. It's far easier to make a faster fighter or missile than a faster, say, bomber. This has gone back and forth over the years, see schellbomber for instance, but invariably the defense had the easier job - especially once they had radar and interceptions were arranged in front.
The real reason speed is useful, especially in the 50s and 60s, was that the interception process itself was manual. So if the guy on the ground has a radar with a 200 mile range against your bomber and you're flying Mach 3, you're going to be overhead in 5 minutes and disappear in 10. That leaves very little time for the operator to arrange an interception. If the interceptor starts on the ground, it's not going to happen, period.
That, of course, changed with the introduction of SAMs. Now the only need for the operator is to figure out roughly where you're going and alert the closest SAMs along that line. Five minutes is lots of time for them to get ready.
There is, of course, the advantage of confusing the defense network as a whole; Moscow is maybe 15 minutes from the coast in a B-70, and that doesn't leave lots of time to get prepared. But in the era of ICBMs, that too is enough time.
And so speed sort of went away and was replaced by low-level flying, jammers, SRAM and so on. If you're going to blast your way through the defenses with SRAM, doing so quickly doesn't really offer much of an advantage, the missile is going much faster than you ever will.
But all that is old is new again, and speed is once again showing some advantages. In the case of the F-22 the idea is simply to have enough performance that the combination of altitude, speed and stealth/detection range keep you out of the lethal volume of the missiles below you. So against something like the S300, the missile has excellent performance and can shoot you down, but it will only see you at short ranges and you're way up in the air, so by the time they get a tracking solution you're already out of range. That's significantly more difficult to pull off if you're flying 30% slower.

What does SRAM mean ?

Short Range Attack Missile, but the paragraph makes hardly sense to me. Probably it means, that your own speed doesn’t matter a lot, when you are at least capable to launch it within some more distance than a bomb?

Basically if you’re going to blow up all the defensive emplacements it doesn’t matter how fast you fly to them as long as the missile gets there first.


text:
What different intake designs are there, and what are their pros and cons?
I noticed that over the years (on fighter jets specifically) there have been many different methods of directing air into the engines. Primarily, the nose-intake, side intake, and underbody intakes have been very popular with many different designs.
Could somebody explain what the pros and cons behind each type are?

This may answer the question for you. And this is a possible dupe of at least part of it.

What? @ymb1 that doesn't explain like 8/9's of my question. There are tens of different intake designs please if you want to call a dupe read my whole question and figure out the answer first. And thanks Dave that did answer my question if you could put that in an answer post and just link the URL I'll accept and upvote it.

It is mostly a tradeoff between complexity and speed.
High speed inlets not only fundamentally need to be more complex for efficient operation (more oblique shocks required before the normal shock), but they also must operate at all the speeds lower than their design speed (unless it is a boosted missile or something like that).
This figure is from 1980 and it illustrates this tradeoff.
I recall reading somewhere that a huge amount of the F-15 development costs went into the last 0.2 Mach number capability (i.e. 2.3 to 2.5) -- largely driven by added complexity in the inlet system.

The big thing that is different with modern military aircraft is the requirement for stealth.  So modern supersonic inlet design is a tradeoff between complexity, speed, and stealth.
If you are unfamiliar with the need for more shocks for higher speed, here is the fundamental tradeoff.  Total pressure ratio is the fundamental efficiency measure of an inlet.  You want it to be as close to 1.0 as possible.  This is easy for subsonic engines.
Once you are supersonic, you need to slow down the air before it reaches the front face of the fan.  You want the flow to eventually be subsonic, so your final shock is a normal shock.  A single normal shock at high Mach number is a very strong shock and is a disaster for your inlet pressure ratio.
Consequently, we use one or more oblique (or conical) shocks before the final normal shock to slow down the flow gradually.  As it turns out, the optimal solution is to have each of the shocks have equal total pressure ratio.


text:
Does a nuclear weapon (B-61) equipped F-35 have the same nuclear confirmation failsafes as other nuclear device delivery aircraft?
Several sources cite that the F-35 will be able to be modified or simply equipped to carry some variant of the B-61 nuclear bomb. However, I know that most strike aircraft such as the F-15 Strike Eagle seat two crew as so for nuclear weapons there must be confirmation of arming the weapon by both crew members. No variant of the F-35 seats two, so I assume that there must be some way of having two-factor authorization of this protocol anyways. Is there a publicly known practice of arming nuclear devices on the F-35 or any other single seat aircraft or were the sources stating it could deliver the B-61 incorrect?

Which sources are you referring to?

Many. News organizations are announcing all the time about operators of the F-35 intending to field nuclear weapons on that platform. Regardless of whether they will implement this, the F-35 is capable of it, and that raises the issue in my question about how the decision to arm and launch the weapon in a single-seat only fighter is made.

Would these aircraft normally carry nuclear bombs around? If not, the act of equipping one is at least one level of authorization; if not to use it, at least to acknowledge that it may need to be

No, it's not solely a nuclear weapon delivery platform, but it is certainly capable and equipped of delivering a B-61 without extensive modification. In other words, the nuclear weapons for aircraft of its size are certainly part of the F-35's arsenal.

There was a time in US military history when there was a lot of prestige and funding for nuclear weapons and their delivery systems. At the time the USAF was divided into SAC and TAC, strategic and tactically air commands, or if you prefer the bomber and fighter mafias. SAC was getting more attention and funding as Nuclear weapons delivery was its primary mission. TAC developed various programs that also used nuclear weapons such as air to air rockets with nuclear warheads and toss bombing, releasing nuclear weapons on a long trajectory as a fighter was claiming.

Traditionally many single seater aircraft have had nuclear weapons capabilities.
To name a few:

A-4
F-104
F-105
F-84
F-16
A-7 (I think)
F-102
F-106
F-88
F-101

This list isn't exhaustive. The release of the weapon will typically be authorised before takeoff, the pilot then having the electronics on board to enter the final arming codes that will bring the weapon life. I'm not in the know about the exact procedures here, but my guess is someone on the ground acts as the first of the two keys before the flight starts, and the pilot entering his codes into the arming console during the flight acts as the second. This is far more reliable and less error prone than having the code transmitted to the weapon during flight over a radio link which may be jammed, detected, or simply not work in a nuclear war scenario.

I'm such an idiot I completely forgot about these other strike aircraft! slaps head Yes unless anybody finds a super long list I'll probably accept this answer. Thanks for aiding a stupid amnesiac!

The F-35 is positioned very much as the successor to the F-16 (single-engine single-seat multi-role fighter, sold to NATO allies). And the F-16 definitely has this role, even those sold to NATO allies who do not have nuclear weapons themselves.

Bingo, and let's not forget the Army can deliver tac nukes as well.  I would keep my F35s with the Spitfires and Hurricanes, and make sure the air control role is fulfilled.  Even a BUFF could come in low and deliver stand off tactical support, but I would call the Army first and ask if they needed it.

@RobertDiGiovanni I'm not sure the US Army still has a nuclear capability. Lance was retired, so were the nuclear artillery shells and I think the nuclear demolition charges/mines. Longest range artillery rockets the Army has right now I think are MLRS, and AFAIK no nuclear version of that was ever created.

Which brings us to the question as to why we would mount a B-61 on a F35 anyways.  We could, but should we?  For what purpose?  If the military decides they need it, they will have it.  I wonder about range and survivability.  Would have to see applications.  Any type of nuke would be a desperate move and would make a mess of the place, inviting a response in kind.

Well, in a tactical situation the F-35 should have greater survivability and chance of successful delivery than other small, fast strike aircraft, so once the F-35 is in large deployment numbers I'm sure it would be the first choice to delivery something like the B-61 if needed.

Well, my fault for dabbling in classified areas.  IMHO the F35 is a spunky point defender but absolutely lumbers along 300+ mph slower than interceptors and has limited range.  The F22 might be the better choice for penetration and delivery, or a stealthy stand-off cruise.  The F35 will shine as a closer in tactical support aircraft (yes, at least try one with the Gau-8 30mm), and the Navy version will be tough to turn with.

@RobertDiGiovanni the F-35 was designed as a multi-role aircraft, not a point defense fighter. Its intended mission is to provide ground support and penetration strike missions in addition to supplementing the F-22 in the area air defense mission. A nuclear capability fits into that mission, indeed as an extreme measure not to be taken lightly. It's no different in that regard to the F-16 being nuclear capable, or previously the F-104G.

Agreed there, but it's a little like what you want to do in high school, what you try to do in college, and what you wind up doing professionally.  I hope it works out, but F35 is a little smallish and slowish to be wandering away from home territory.  The Navy and Marine versions are very valuable, the Air Force one, we'll see.


text:
Why does the F-16 canopy have a K-shaped 'latch'?
Why is the F-16 canopy latch (the yellow painted part) shaped like a K? It's a very funky shape, and I'm wondering if that functions as more than just a latch.

Are you asking about the yellow thing?  Doesn't look like a normal part of the aircraft, but rather something that's installed during some sort of maintenance or other operation to prevent certain things from being activated.  What's the source of that photo? The original source may have a caption that helps understand what's shown there.

I edited the question to clarify what I'm asking about, and it is a permanent part of the plane.

How do you know it's a permanent part of the plane? Do you think 'spider guard' refers to the yellow thing?

The function of the form is to act as a throttle stop when the part is in the position shown in the picture. It prevents full movement of the throttle when canopy is not securely closed and sealed.
When the canopy is closed, the latch is moved by pushing the bottom part of the latch towards the outside of the plane. This moves the throttle stop out of way and actuates the canopy seal.
See this Youtube video for an example, latch operated at 0:25.


text:
Who owns wrecked airplanes in international waters?
Reading about a Spanish treasure ship, I found that it eventually created a dispute between the company that found it (Odyssey) and the Spanish government, so the following questions came to my mind (focused on an international ocean wreck):

Is the same ownership law applicable to wrecked ships and wrecked planes?
Is there any difference between floating debris and sunk debris?

More specifically, regarding Malaysian Flight 370, who owns the debris discovered at La Réunion?

Good question -- doubly so considering there are some other aircraft that are still at least partially lost at sea, I'm sure.

I have a friend who bought a Piper Apache that was damaged by a hailstorm. Though the airframe was condemned, the engines, props, avionics, and other miscellaneous parts were still useable. Somehow there's a disconnect between the question you asked and its explanation.

I think the OP is talking about an aircraft that has fallen into the ocean, broken into lots of little pieces, etc... A plane obviously doesn't lose its ownership because its merely damaged, or even severely damaged, but the situation can be a bit different if its many parts are floating around the world. Similarly, there's a difference between a broken boat and The Titanic.

Related: Aviation archaeology. Extract related to the US: "As a part of federal air regulations, NTSB Part 830, protects any aircraft whose accident cause is under investigation."

@ZachLipton I am focused on the ocean. Which law applies there? Wil that imply that any liability due to any damage produce by the ship during its lifetime will remain on the previous owner? Second question will be... if no ownership is demonstrated (specially in the cargo) who gets the ownerships? Plane owner or salvior?

@mins that is only covering part of my question. Is only retricted to US law (so not applicable to international part of the ocean and other national places) and is only covering the planes which are under investigation. Protect does not cover properly as well ownership.

@TrebiaProject.: True (I don't know the answer, this is only an element that can be used for an actual answer). My suggestion for the flaperon: I think the state (France) owns it, as anything from a wreckage in the 25 km area from the shore is declared to belong to the state. But this needs to be confirmed.

I suggest a migration to law.SE.

@kevin I think is an aviation related law topic, is like proposing aerodynamics of wing to be move to physics. For investigations is really relevant. Taking the previous example it might be the case the state could have requested compensation from Malaysia for a debries they own. That could create difficulties in the investigations.

I would agree with @kevin. While this refers specifically to aircraft, I would venture to say the same international law applies to aircraft wreck debris as does ship wreck debris, and, therefore would be a legal question. Questions of ownership are usually legal issues...

Insofar as it relates to MH370 the treaty sections Pondlife quoted would probably work quite smoothly if it were found by a government or someone working on behalf of the govt. The question arises as to what happens when James Cameron goes and finds it. (Inevitable, am I right?)
If it is located by a private party then the law would not be quite so clear. It would fall to courts and there would be legal claims falling under admiralty law, salvage law and those might even be superceded by laws governing criminal investigation at sea.
Generally under ocean salvage law the original owner continues to own it, but the salvaging party is entitled to a substantial award or prize. To complicate matters, there are two international conventions on salvage law, one from 1910 and a second one from 1989. Some countries recognize one of them and object to the other.
If Malaysian Airlines is no longer in business when it's found that will make things even more unclear. Probably the best analog would be the Titanic case. The company that recovered most of the artifacts sued to be declared owner. A US court declared jurisdiction and ruled that as compensation for the cost of recovery they had the right to display the items, but they do not own them.

After a series of court battles, an American company, RMS Titanic Inc (RMST), emerged as the owner of the salvage rights, allowing it to keep possession and put on touring display the 5,900 artefacts it has lifted from the ship during six dives.

From an article in The Guardian
So far no one owns them since White Star Line is long gone. The US and UK quickly hashed together a treaty to declare them a public memorial so the artifacts can't be sold off to private collectors.

An international agreement signed by Britain and the US designates the Titanic as an international memorial and seeks to protect it from being plundered or damaged by unauthorised dives.

from the same article*

With all these things at play there is simply no telling what would happen with it.

Wow, looks quite complicated. Moreover, you mention the salvage law, but after  reading about it I understood that there are some countries that have not signed the agreement, so any citizen from that country is "outlaw" in that context. I guess your answer is "complex and depending on the nationalities of the parties"

I'm sure if a private party finds it there'll be 50 years of court cases. Of course, I'm not sure what a private party would stand to gain from it unless they're one of these conspiracy people that think there's $20 billion worth of gold bullion aboard

ICAO Annex 13, Aircraft Accident and Incident Investigation, says that the country where the aircraft is registered is responsible for investigation and it (or the operator's country) makes the final decision on what to do with the wreckage.
The "State of Registry" is responsible for investigation if the accident is in international waters:

State of Registry
5.3 When the location of the accident or the serious incident cannot definitely be established as being in the territory of any State, the
State of Registry shall institute and conduct any necessary
investigation of the accident or serious incident. However, it may
delegate the whole or any part of the investigation to another State
by mutual  arrangement and consent.
5.3.1 States nearest the scene of an accident in international waters shall provide such assistance as they are able and shall, likewise,
respond to requests by the State of Registry.

And it (or the "State of the Operator") decides who should take custody of the wreckage once the investigation is complete:

Release from custody
3.4 Subject to the provisions of 3.2 and 3.3, the State of Occurrence shall release custody of the aircraft, its contents or any parts
thereof as soon as they are no longer required in the investigation,
to any person or persons duly designated by the State of Registry or
the State of the Operator, as applicable.

Practically speaking, I assume that once an investigation is complete the wreckage is either scrapped or returned to the operator (airline) if it still has any value.
In the case of MH370, that means that Malaysia as the State of Registry (and the State of the Operator) is responsible for investigation and for ownership of the wreckage. But I'm not a lawyer, so if you want a definitive answer then I suggest asking elsewhere.

It should also be noted that the NTSB has a policy that if the plane is of american build (Boeing etc.) they will send agents to the investigation if they can legally get them into the country. This is a courtesy for assistance but in some cases accidents are partially investigated by the NTSB (here in the US sometimes) if the country of origin does not have the facilities to cary out the investigation properly.

This answer is relevant where the aircraft is in the hands of investigators. It doesn't really cover the question of who is the current legal owner of the currently submerged hulls of 9M-MRO and F-GZCP. The investigation of the latter has been completed, insurance claims all paid, yet the hull is still sitting in international waters. Can anyone go and haul it up and take it home or sell it etc?

Reading the material it looks that the "state of registry" or the "state of operator" decide after the accident who takes the ownership.


text:
Why do entertainment system headphones on aircraft have two pins?
In most commercial flights where headphones are provided for inflight entertainment they have two pins, unlike single pin connections which we use on the ground (e.g. for mobile phones).
Is there a particular reason why it is done that way?
One reason could be that people can steal a single pin headphone. But still it is not compelling enough reason.

One reason - there are probably others - is that most airlines used to charge money for headsets (I think some still do on domestic flights) and they wanted to make sure that passengers couldn't just bring their own, so they created a deliberately incompatible connection to 'force' people to pay. But the last headphones I bought came with an airline adapter and some newer aircraft have regular single-pin connectors so I guess this is changing.

All of the aircraft that I've been on lately that had headphone plugs had just a normal single-prong 3.5mm jack on the IFE systems in economy, though I think the ones that provided noise-cancelling headsets in business class used special connectors (since they need to provide power to those headsets.)

@reirab Yes, the extra pin for noise cancelling power is quite normal in my experience

The three main reasons are:

Prevent theft of headphones due to incompatibility with home systems
Redundancy, if one connector breaks, the other will still provide audio
Before the 3.5mm jack was used, a pneumatic system was in use, which required two connectors.

This question has been asked on different websites already, but here is a detailed explanation that sums it up nicely:

There are a couple main reasons:
First, the airlines were trying to prevent theft of headphones. The two-pronged plugs have been around on airplanes since way before the airlines started charging for headsets. Back then, headphones were not usually easily carried around as the portable earbud style had not become popular yet. By using a two-pronged setup that is not used in most other audio systems, the motivation for passengers to steal the headsets went down immensely.
The second reason is redundancy. When a standard stereo headphone jack with three internal connections (right, left, and ground) breaks, you will often lose audio in both the left and right channels. However, with the two-pronged design, if one of the jacks breaks then there will still be audio going through the other channel. While this is annoying for the user, it is an easy way for the airline to defer maintenance on that individual seat's audio system until both the left and right channel are non-functional.
The two-prong design is a relic of the past, before headphones were bundled with so many of the mobile devices we now buy. Planes with updated inflight entertainment (IFE) systems usually have the standard stereo jack as most passengers prefer using their own headsets now. Slowly these old connectors will be completely phased out.
Another less obvious (and probably less likely, but interesting nonetheless) reason, though, is based on airline complacency. Airlines, especially US based airlines, are notoriously slow in changing their tactics. Back before the 3.5mm jack became the standard for headphone audio connections for IFEs, airplanes used a pneumatic headphone design. These headphones were similar to stethoscopes where hollow tubes would be plugged into the armrest which had actual soundwaves coming out (instead of analog electrical signals). These systems were much more reliable than the standard electrical system and the headsets themselves were very cheap to replace. Since the pneumatic system required two separate plugs for the left and right channel (since you cannot mix physical sound waves into a single hole), all armrests were designed with two holes for audio. Airlines were likely so used to having two jacks for audio that they continued with the same design when they switched to electrical audio signals.
(Source: www.quora.com - Author: Raj Misra)

Glad you covered the old "sound tube" style - I remember those, and the offers from the flight crew to take them with you when you left. That always garnered confused looks from the pax, as they were useless for anything but the aircraft.

@FreeMan Credit where credit's due - I only quoted from the original author I linked to in my answer.

Aye, but you could have left that part out and no one would have noticed... ;) BTW - is your link the reference to the quote?

@FreeMan Yes, I edited it now to make it more clear.

Talking about Quora on StackExchange is a ... taboo.

Sound-tube systems go back a long time.  At an antique phonograph and music box show, I saw a phonograph which was attached to about a dozen headsets, so an attendant in a hotel lobby could allow waiting guests to listen to music for a fee; this was before the days of electronic amplification, so the headsets were all pneumatic.

Current design include twin plugs compatible with single ones too...

@supercat Sound tubes are still around too: The headset I wear every time I fly uses sound tubes (granted they're connected to an individual speaker for each ear, and go to a standard electric plug, but they're still sound tubes).

@voretaq7 What's the reason you use sound tubes & not just electrically driven magnets?

@curious_cat That's just the way the headset is designed. Seems to make more sense than constantly flexing the wires for the earpiece though.

@Farhan Why is it taboo, and where can the policy be found?

This is still currently the case on Qantas A380 I just feels between LAX and SYD. They provide a fragile adapter on the complimentary headphones that provides a single jack, but once I broke all of those I found I could put my headphones in either of the two jacks just right and get stereo output just fine


text:
How can I tune a frequency like 121.62 on a comm radio?
On my radio, an ICOM A210, I can't tune 121.62 (the clearance delivery frequency at KMSN). How can I tune a frequency ending in 2?

... and your question is?

This page shows the frequency range as 118.000–136.9xxMHz.

Can you explain exactly how you're trying to tune the frequency and why you can't select 121.62? What exactly happens?

Shouldn't you call the vendor/manufacturer on this rather than ask on Aviation.SE?

Icom has manuals available on-line, for free, have you RTFM?

Can you contact them on 121.625? The frequency you list (though it's that way in the A/FD also) may be a typo, since airband in the US still uses 25kHz spacing.

@NathanG Most 25kHz radios drop the last digit, so when you put in 121.62, it is actually tuning and using 121.625.  Others show the last digit, so tuning 121.62 would be impossible, although as you say, 121.625 is most likely what he wants.

As a complete guess, you're trying to tune 121.620, but you should just be tuning 121.625. From AOPA (emphasis mine):

All aviation communication, VOR, and ILS frequencies are in the 100
  MHz band, so the first number is always "1." The hundredths digit can
  be only 0, 2, 5, or 7; 1xx.x2 implies 1xx.x25; and 1xx.x7 implies
  1xx.x75--when a frequency is assigned, the ending "5" is often
  omitted. Trailing zeros in the hundreds and thousandths positions are
  always omitted in voice transmissions.

The standard frequency spacing in the US is 25kHz.
Omitting the last digit is also described in the FAA's ATC instructions:

The separate digits of the frequency, inserting the word “point” where the decimal point occurs.

(a) Omit digits after the second digit to the right of the decimal
  point.

They include this example:

135.275 MHz “One three five point two seven.”

And although this probably isn't your issue, it's worth noting that some radios tune in 50kHz increments by default, unless you pull out (usually) the tuning knob to enable 25kHz tuning. I've been momentarily confused by that several times in unfamiliar aircraft. I assume this isn't the issue you have, though, since the manual for the A210 says it uses 25kHz spacing.

I called KMSN tower, they said 121.625 should work as well or, just call ground which is what I did last time I was there.

121.625 should not work "as well", it is the frequency that should work.

Just to put a point on the answers already here, there is no actual assigned aviation frequency 121.62. You add a 5 if the 5th digit is a 2 or a 7. Some radios display the 6th digit, some don't.
It's further confusing where 8.33 kHz channels (in Europe, and in some special cases like flight test frequencies or company frequencies) are used. Between 121.600 and 121.625 are two other frequencies, which are actually 121.60833... and 121.61666... MHz, referred to by their "channel names" as 121.610 and 121.615. Eurocontrol mandates saying all six digits for the split channels.


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Can a non-US citizen (or entity) own an N-registered aircraft?
Distantly related to this question, but can a non-US citizen (or corporation) own an N-registered aircraft?

Nothing in the regulations seems to preclude it - but there are some conditions you have to meet per the FAA:

An individual who is a United States citizen,
A partnership each of whose partners is an individual who is a U.S. citizen,
A corporation or association:

organized under the laws of the U.S. or a State, the District of Columbia, or a U.S. territory or possession,
of which the president and at least two-thirds of the board of directors and other managing officers are U.S citizens, and
in which at least 75% of the voting interest is owned or controlled by persons that are U.S. citizens,

An individual citizen of a foreign country lawfully admitted for permanent residence in the U.S.,
A U.S. governmental unit or subdivision
A non-U.S. citizen corporation organized and doing business under the laws of the U.S. or one of the States as long as the aircraft is
  based and primarily used in the U.S. (60% of all flight hours must be
  from flights starting and ending within the U.S.)

(emphasis added)
So Toyota could not buy an aircraft and register it to their main company in Japan  on the US registry, nor could they buy & register it under a US Subsidiary and subsequently fly it off to Japan to live out the rest of its days shuttling executives around Asia.
A Toyota executive with Permanent Resident status could buy themselves a nice Cirrus and register it on the US Registry though.

There are plenty of N-reg aircraft in Europe that will never see the US again. See also this question: http://aviation.stackexchange.com/questions/8750/why-do-ga-pilots-in-europe-operate-n-reg-us-aircraft

@SentryRaven Indeed - if they're owned by one of the first three types of entities there seems to be nothing wrong with that. (And if they're owned by the forth kind of entity? Well there's the letter of the law, the spirit of the law, and the practice of the law - the three are often only loosely related. :-} )

I've wondered about how people get an N registration as a European. Guess they set up a paper company or non-profit in the US for a token registration fee at some chamber of commerce, they're now a US company, and the company owns the aircraft?

It would be ironic if Chrysler (now owned by Fiat) lost the right to own an N-reg aircraft based on the 75% voting interest owned by US citizens rule. (Since Toyota was brought up as an example in the answer.)

@FreeMan That 75% thing is an interesting provision, but it's not the only applicable one - it deals with US corporations, while the question is about NON-citizens (and thus NON-US corporations by extension). Fiat could simply re-register all the aircraft under Fiat if necessary (doing business in the US, and meeting the 60% requirement).


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What aviation-related movies are there?
This question aims to serve as a Community Wiki resource.
Feel free to edit the list of aviation-related movies below!
Related: What aviation-related TV shows are there?

Meta discussion simultaneously started: Are these questions on-topic? TV shows/movies

I love these I hope they stay :)

It is not about aviation, it is about tv shows.

Isn't this a list question?

Action

Top Gun

Comedy

Airplane!
Pushing Tin

Drama

Airport
Cloud Dancer
Flight
Ground Control
The Aviator
The Right Stuff

Factual

One Six Right
Speed and Angels
United 93

Turner Classic Movies

TCM lists 43 aviation movies in it's catalogue

Miscellaneous

Sky Captain and the World of Tomorrow
Airport
Airport 1975
Airport '77
Concorde... Airport '79
Wings

Best picture, 1st Academy Awards (1927)

Fire Birds
Air Force One
633 Squadron
Independence Day
Independence Day: Resurgence

Coming soon to a theatre near you!

Bombers B-52
The Bridges at Toko-Ri
A Gathering of Eagles
Air Cadet
Those Magnificent Men in Their Flying Machines or How I Flew from London to Paris in 25 hours 11 minutes
Bat*21
The Flight of the Phoenix

The good one with Jimmy Stewart. Not the remake.

No Highway in the Sky
Flight of the Navigator
Flightplan


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What are the main differences piloting Boeing vs. Airbus aircraft?
What are the main differences in flying a Boeing vs an Airbus aircraft?
Ignoring cosmetics, e.g. nose/window shape (see How can I tell apart an Airbus from a Boeing?)

On a Boeing, the pilot outranks the auto pilot.

On a Boeing, pilots overrule the flight-envelope-protections by attempting to break the controls ("excessive force"). On an Airbus, pilots overrule the flight-envelope-protections by pressing two switches (2xFAC).

Airbus' speak French, mon dieu! It's incredibly annoying.

@EdwardFalk As in an Airbus.  The whole Boeing vs Airbus nonsense, to me, sounds like "I don't trust a wing that's not covered in fabric such that I can repair a hole with some cloth snipped from my breeches".  FBW and increased automation is inevitable.  It is part of the contribution to ever more safe flying with most years making a new record for lower fatalities in absolute terms.

A colleague of mine at another company who switched from Airbus to Boeing and vice versa a few times gives his account here (and at a few other places in the same blog): https://mmsba.wordpress.com/2017/05/01/airbus-or-boeing-part-2/

Pilots on a Boeing actually fly the aircraft. Airbus pilots are on the aircraft only to get a free ride from the auto pilot between layovers, to give inspiration to the passengers and make occasional clever PA announcements..

On a pilot-vs-FBW system perspective, as mentioned in the comments to the question, the most notable difference is the authority priority:

Boeing trusts more the pilots: they can supersede the Fly-by-wire automatic commands by exerting enough force on the controls
Airbus trusts more the FBW system: if the system is fully functional ("Normal law") it will always have priority over the pilots to protect the aircraft and keep it in the envelope, but they still have room for "non-standard" maneuvers, e.g. commanding bank angles between 33° and 60°. The autopilot can be activated and de-activated at will by the pilots, and it sits on top of the FBW envelope protection.

One of the most famous examples where this comparison emerges (and the subsequent debate about which approach is better) is the China Airlines 006 accident.
I won't go into detail, there is the accident report that will provide much more information that I can remember, but suffice to say that this 747 was recovered from a quite unusual attitude

As mentioned in the wiki article, the report states that the passengers were subject up to 5 gs during the maneuver and the stress on the horizontal tail surface has been so great that as a result it was damaged:

The usual argumentation goes along the lines that, would this had been an Airbus, the pilots would not have been able to save the aircraft.
See for example this PhD thesis at page 184 of the pdf, section 6.2.3 "Pilot Authority at the Boundary":

It is likely that if the aircraft had prevented the crew from initiating control commands that would lead to aircraft damage, the aircraft (and passengers) would have been lost.

The problem with such a comparison? It focuses on the recovery after the unusual attitude was achieved and totally forgets about the sequence of events that lead to it or, to the very least, assumes that an Airbus would have responded in the same way to the preceding events (then why make a comparison at all?)
An honest comparison would take into account this and acknowledge that an Airbus in Normal Law would not enter a spiral dive in the first place, even with an engine out, as bank protection/attitude-hold would prevent it.

In fact the 33 degrees is limit to which the control system returns after upset to higher bank, for example turbulence. But since with centred side-stick the control computer aims for zero roll rate, it would actually stop the roll after a few degrees (this is well documented behaviour in case of engine failure; banks very slightly and maintains shallow turn until rudder trim is manually dialed in).

@JanHudec, yes, I have specified "attitude-hold" for the reason you cite. Feel free to add it to the answer.

If I recall correctly, Airbus has a not-very-widely-known Abnormal Attitude Law to allow recovery of precisely these situations where the Normal Law would not be sufficient. I seem to recall it’s mainly a direct control of surfaces. Maybe someone can dig out a proper source other than that obscure corner of my mind...

Boeing aircraft primarily feature a traditional "yoke" system, which allows pilots to directly control the plane:

In contrast, Airbus aircraft use a "fly-by-wire" system via a joystick which transmits electrical signals to control the plane:

Airbus aircraft limit pilots' capabilities in situations that require extreme action to be taken; the computer may prevent the pilot from pushing the plane past its safe ranges, which could be necessary in case of an emergency.
Boeing aircraft leave ultimate control mostly to the pilot.

"which could be necessary in case of an emergency". It'd be good if you could describe a situation where it would be necessary to go beyond these limits. Also, most newer Boeing aircraft also use fly-by-wire systems, though pilots still use a yoke to control the aircraft.

"Capabilites" sounds biased. In some situations this may translate into "potential to do major harm". It can go both ways, and is ultimately a design philosophy question.

@Qantas94Heavy I encourage you to write your own answer! We're only at a 1.5 ratio atm.

B777 uses fly-by-wire as well. fly-by-wire v.s. direct hydraulic is a technical detail. The control laws are the significant difference.

@Qantas94Heavy "necessary to go beyond these limits"? You fly out of a cloud and heading straight for you is another aircraft, perhaps 2 or 3 seconds from collision. With a Boeing, you can jerk the controls enough to avoid a collision, even though you may pop rivets and bend metal. With an Airbus, it may not let you make such a dramatic maneuver, to prevent damage to the aircraft.

What you list as a draw back is also a benefit.  Airbus will stop pilots from pushing the plane past its safe ranges all of the time, even when there is no emergency.

Can't this argument be settled once and for all by a careful study of incident and accident reports? Or are there too few for a meaningful conclusion? (in which case I'd argue the difference is fairly inconsequential)

In laymans terms, in a boeing, the pilot commands. In an airbus, he is just a voting member.

@HCBPshenanigans  how it comes then that recently an airbus has been killed by a pilot? How the plane allowed the pilot to fly into the ground?

@PhilPerry "You fly out of a cloud and heading straight for you is another aircraft, perhaps 2 or 3 seconds from collision." ATC should never allow this situation to develop. In case of a failure in ATC, still TCAS would warn the pilots long before your postulated "2-3 seconds from collision". TCAS RAs are issued such that pilots have sufficient time to safely react. The only case I can see in which such a situation would develop is if there is a simultaneous failure in ATC and TCAS onboard both aircraft.

Big difference is on Boeing with a yoke, it is like two linked steering wheels in a  car.  The pilot not flying can easily see what the other pilot is doing with his controls, as the yoke in front of him moves along with the other pilot's inputs.
On the airbus models with a side stick, the pilot not flying cannot see what the other pilot is asking of the controls.  This contributed to the situation where Air France stalled and fell into the sea without the pilot in the left seat realizing that the pilot in the right seat had his controls calling for full pitch up.  (The opposite of what would get them out of a stall.)

Although not as complete as other answers, the fact that a pilot does not see what the other pilot is doing is a very good point to mention. It is also worth noting that in the case of AF447, the autopilot safe envelope protection was disabled when they lost the airspeed sensor. Despite the fact that the sensor went back to normal shortly after, the autopilot had relinquished total control to the pilots (no more safe envelope), allowing the copilot to set the plane in this stalling attitude (the autopilot working normally would never have allowed that).

so..it's possible to have total control for the pilots...

Airbus (A320+; A300 and A310 have traditional controls) uses flight control laws. In flight, the side-stick input does not indicate desired position of control surfaces, but desired wing loading and roll rate. The flight computer takes care of trimming the aircraft for straight flight at current speed and balance.
Boeing uses traditional controls, where the position of control column corresponds to position of control surfaces and force on the control column corresponds to force on the control surfaces. This means that the pilot has to adjust the trim manually when not using autopilot.
The Airbus system is more convenient, but it has its disadvantages. The neutral stability means that the aircraft won't tend to maintain speed by changing pitch, so the pilots have to monitor speed more carefully. It really needs the flight envelope protections to be considered safe.
Boeing has flight envelope protections since 777, so that's not a difference any more. I don't think they are adding them to new versions of 737 though.

Airbus has nevertheless a velocity-hold control loop, so velocity will be maintained. The throttle lever while in normal law in cruise only sets the maximum allowed thrust, but it does not fix it in any way.

@Federico: That's not part of the control law. It's auto-throttle just like in any other large aircraft and can be disengaged. Of course pilots keep it engaged as it simplifies the handling.

Airbusses still have positive stability; they just have slightly-less-positive stability than (e.g.) Boeings.

@Sean, I don't think Airbuses have any less natural positive stability than Boeings, but in normal and alternate flight law the control system undoes it, providing a artificial neutral stability.

My 2 cents:
There are a few things mentioned here.

The sidestick and autothrust systems of the Airbus are different than    the conventional yoke  and autothrottle system on the Boeing.
The Airbus technology and quiet cruise was great; the Boeing's    tactile feel  and crosswind capabilities were very good.
There is a difference in the length of the fuselage, making taxiing    different. The handling characteristics in flight are very similar.

"Airbus technology and quiet cruise was great" is just an opinion. "There is a difference in the length of the fuselage" is meaningless. Yes, not all planes are the same length. But not even all Boeing 737s are the same length!

@JanHudec the A320's engines are further outboard than the 737's, so despite having more vertical ground clearance, they'd actually strike the ground at a similar bank angle. And in either case, the wing tip would strike first... the engine would be the least of your problems compared to the fact you'd have just sheered/damaged a wing or be cartwheeling/groundlooping down the runway.


text:
What effect would an air-to-air GPS jamming system have?
I just noticed an interesting AIC: NOTIFICATION OF GPS JAMMING EXERCISE – HEBRIDES RANGES DURING PERIOD 21 JULY - 1 AUGUST 2014.
PDF available on Eurocontrol (official) or Scribd (mirror).
The Ministry of Defence is planning a GPS jamming exercise:

Jamming will occur across the 24 MHz bands centred around 1227.60 MHz and 1575.42 MHz. A Falcon 20 aircraft will be equipped with 2 high power jamming pods (1kw), one for each
  GPS frequency.

What effect would this have on a plane entering the jammed airspace?
Related: Can a GPS signal sent to a plane be spoofed?

Jamming GPS means that the GPS receiver is unable to lock-on to the signal from any satellite.
Presumably, pilots of small aircraft would have to revert to more traditional forms of navigation - assuming they have a GPS based navigational instrument or two.
Pilots of airliners would presumably see alerts and (as with most smaller aircraft?) their flight displays would include non GPS sources such as gyrocompasses or magnetic compasses.
I imagine redundant systems would include other sources of position information such as reception of radio-based omnidirectional navigation beacons, inertial navigation systems and looking out the window.

I read an article a while back (it is also described over at wikipedia) about spoofing GPS signals, making the receiver believe it was somewhere else (or rather moving in a different direction/speed, eventually ending up somewhere else). It is a non-trivial process involving sending the equivalent (but stronger) signals of the current position to make the receiver lock on to the false signal and then gradually shifting it away. I'm no expert on the subject so I can't tell if it's actually feasible, but it seems possible to do.

@falstro There was at least some speculation that this was how Iran captured one of the U.S. drones. I can't remember if that was ever confirmed or not.


text:
Wind speed over which a Canadair fire fighting plane cannot safely fly?
We recently had some forest fires in Athens, Greece while the weather was very windy. The news said it had 8 beaufort of wind speed (34-40 knots, 38–46 mph) and in these conditions it's dangerous to fly the "canadairs" (I think we have Canadair CL-215 and Bombardier 415).
Is this true? What is a wind speed over which one wouldn't want to fly such a plane?

Please cite a reference where the firefighting aircraft were grounded due to WX

The live news kept repeating this. Only 2 helis and 3 aircrafts were trying to help. One of the aircrafts fell nearby. The chief of the town and president of an organisation "protecting" the mountain said that "with these temperatures and 9 Beauforts no system exists that can put out the fire". http://www.spay.gr/index.php/newslist/44-2015-07-20-09-46-16

From that article via Google translate: "the intensity of air (9 Beaufort), no system can extinguish such intensive fire." This is not an aircraft limitation but a problem of the wind making it impossible to extinguish the fire, with aircraft or any other means. I'm going to vote to close as off topic.

@rbp in the end, authorities where just watching the fire and the wind do their thing claiming that is very risky to use airplanes in these conditions. I'll try to find written "documentation" of this in order to satisfy your criteria.

Add a guess, I might say that it’s extremely dangerous for those airplanes to scoop in a fresh gale like that.  Way too easy to catch a wing on those waves and capsize.  That, and taking off and landing in those conditions is going to be treacherous as well. You might consult the Canadair  pilot manual for that aircraft.

The problem is not the wind speed per se, but the combination of factors.
Let's start from the data; this is the METAR for Athens on the 17th of July, the day of the fires:

METAR LGAV 171220Z 03026G38KT CAVOK 32/10 Q1016 NOSIG=

I have highlighted the wind speed data. It says that the wind at Athens airport was on average at 26 kts, with gusts up to 38 kts

26 kts of wind at high altitude would not be a problem for a CL-215
26 kts of wind near ground (to drop the water it has to do low passes) and at low speed (it has to go as slow as possible to be precise) can be highly dangerous, as proximity with the ground increases turbulence. Let's also consider the mountainous terrain around Athen (and the fires were on the side of a mountain), windshear and turbulence were probably quite strong. (See also this question: When crossing a mountain ridge at low height above terrain what consideration is given to turbulence? )
26 kts was the average wind speed, gusts were up to 38 kts, increasing the risks of such operations.

In addition to the above, let's remember that these aircrafts have to fly over fires, that will create additional turbulence through the rising hot air column that they generate. (thanks to David Richerby)
I do not think that a hard limit for such operation exists, as said above is the combination of windspeed, terrain configuration and mission that determines if an aircraft can perform it or not.

Wow, thanks for the detailed answer. Is it possible to find the metar data for a specific long/lat?

@cherouvim METAR is connected to a meteorological station, so usually you can have METAR for airports and a few other locations, but not for an arbitrary lat/long location. remember, METAR is measured data.

makes sense. Thanks.

Downvoted: (1) Va and wind speed have nothing to do with each other (2) there is no turbulence over water because water is not a source of convection.

@rbp (1) try to fly in winds with speeds comparable to your Va (2) usually the fires to be estinguished are not in the middle of the sea.

(1) I misread, I thought you meant loading water into the aircraft (2) I have flown many times with winds exceeding Va. Va in my mooney is 85, and winds speeds at high altitude often exceed that. One of my best flights had 150kt tailwind at FL210, for a GS exceeding 300kts. There's no relationship. Please cite a reference if you can find one

@rbp removed the Va part, is it fine now? [anyway, no problems with tailwind, that's quite a limitation from the most general case]

The structural limits of the aircraft can't tell how much constant wind there is, no matter which way the wind is coming from. They can however tell how gusty it is, and there is a gust line on the V/G diagram.

@rbp I was not limiting myself to structural problems, but anyway, removed the remark to remove problems from the answer. Are there any additional problems in it or can I hope that the downvote will be removed? we can continue the discussion in chat anyway.

Va is determined by structural limits of the aircraft. I still think the answer is all conjecture with not a shred of evidence to back it up


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What is the purpose of the glazed round area atop the Ju 87 Stuka G?
I haven't been able to find any pictures of this feature aside from models, nor any reference to what it is.
I'm going to make a complete guess and suggest it's a searchlight for night-fighting to illuminate the underside of bombers.

Italeri Ju 87 G-2

Hobby Craft Ju 87 G-1

Hasegawa Ju 87 G-1

Please don't change the existing question.  You should ask your second question as a new one.  One question per post.

I think it's a transparent cover for a direction-finding loop antenna. The rear gunner doubled as navigator, and probably needed to check the position of the moveable loop antenna.
Ref.: Luftfahrt Bilder, Texte, Dokumenten   Mittler Verlag 1978 Page 3389

Also this picture showing the loop antenna and the sense antenna.